A related art pressure sensitive adhesive (PSA) label stock has a multi-layer laminated structure including four necessary elements: a face or face-stock, an adhesive layer, a release system and a liner. This label stock, which is commonly produced in roll form including multiple individual labels, is converted into individual labels. An end-user may then apply an individual label to a product. The residual liner, coated with the release system, becomes a waste stream. This waste stream is collected on a rewind stand following dispensing (i.e., the application of labels) and may subsequently be land-filled or sold into low value reprocessing.
To reduce the waste generated through the labeling process, the labeling industry has sought to find ways to affect labeling of PSA-type materials without utilizing a liner and the associated release system, thus significantly improving material and supply chain efficiencies, reducing cost and eliminating an increasingly problematic waste stream. Only limited progress has been made to achieving this goal, commonly in the form of so-called “liner-free” labels and “activatable” labels.
The liner-free labels are typically manufactured by first printing one side of the face stock with an indicia and then applying a release system to the same side of the printed face stock before coating the reverse side of the face stock with an adhesive to create a self-wound label stock that does not include the liner. While the liner has been eliminated, the release system is still coated on the face-stock, and therefore does not deliver the full cost potential of a true linerless solution.
Activatable labels, on the other hand, involve applying a specialty coating or cover layer to the adhesive system (essentially replacing the liner and the release system) or having an adhesive system which is non-tacky at room temperature. In these solutions a separate process, just prior to labeling, either removes the coating/cover layer to “unmask” the adhesive or activates the adhesives through an external stimulus such as heat or liquid. While the activatable labels do indeed eliminate the liner and the release system, and, therefore, a waste stream, they replace them with another, often relatively expensive material, add complexity and may not improve cost significantly. Both liner-free and activatable label approaches have found limited commercial utility.
There remains a need for a true linerless solution that eliminates both the liner and the release system, and does not replace either with another component.